I think my graphic card is not being recognized properlyyou can use the command lshw -c video to obtain info about your video card, you can also use a graphical interface thanks to the command jockey-gtk to manage additional drivers for your system. Please specify what you have done and what you mean with "patch".

Firefox 4 and Firefox 3.6, users cannot start Firefox 3.6Running two different versions of Firefox at the same time or under the same userspace it's really unsafe because no matter what Firefox looks every single time for its own home folder ~/.mozilla and differents versions of Firefox provide different organization and data for this folder, it's true that the basic skeleton contemplates the presence of common files like key3.db or signons.sqlite but it can occur that with a new version some files can be deleted or merged togheter and you can lost your data doing this back and forth.